BerriAI/litellm · error · ValueError

Invalid webhook url value for: {webhook_url}. Got type={type

Error message

Invalid webhook url value for: {webhook_url}. Got type={type(_env_value)}

What it means

Error "Invalid webhook url value for: {webhook_url}. Got type={type(_env_value)}" thrown in BerriAI/litellm.

Source

Thrown at litellm/integrations/SlackAlerting/utils.py:37

def process_slack_alerting_variables(
    alert_to_webhook_url: dict[AlertType, list[str] | str] | None,
) -> dict[AlertType, list[str] | str] | None:
    """
    process alert_to_webhook_url
    - check if any urls are set as os.environ/SLACK_WEBHOOK_URL_1 read env var and set the correct value
    """
    if alert_to_webhook_url is None:
        return None

    for alert_type, webhook_urls in alert_to_webhook_url.items():
        if isinstance(webhook_urls, list):
            _webhook_values: list[str] = []
            for webhook_url in webhook_urls:
                if "os.environ/" in webhook_url:
                    _env_value = get_secret(secret_name=webhook_url)
                    if not isinstance(_env_value, str):
                        raise ValueError(f"Invalid webhook url value for: {webhook_url}. Got type={type(_env_value)}")
                    _webhook_values.append(_env_value)
                else:
                    _webhook_values.append(webhook_url)

            alert_to_webhook_url[alert_type] = _webhook_values
        else:
            _webhook_value_str: str = webhook_urls
            if "os.environ/" in webhook_urls:
                _env_value = get_secret(secret_name=webhook_urls)
                if not isinstance(_env_value, str):
                    raise ValueError(f"Invalid webhook url value for: {webhook_urls}. Got type={type(_env_value)}")
                _webhook_value_str = _env_value
            else:
                _webhook_value_str = webhook_urls

            alert_to_webhook_url[alert_type] = _webhook_value_str

    return alert_to_webhook_url

View on GitHub (pinned to 6c2dcb801b)

Solutions

1. Set the webhook URL environment variable to a string URL, not another type.

When it happens

Trigger: Thrown at litellm/integrations/SlackAlerting/utils.py:37 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of BerriAI/litellm@6c2dcb801b (2026-08-15). Data as JSON: /api/errors/5796e49ef4f3b4e8. Report an issue: GitHub.